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WOLF BLITZER, CNN ANCHOR: I'm Wolf Blitzer. We want to welcome our viewers in the United States and around the world. You're in THE SITUATION ROOM.

Federal authorities say three of Dzhokhar Tsarnaev's friends agreed to cover up his tracks after they recognized him in photos released by Boston bombing investigators. This breaking news happening right now. The three 19-year-old suspects appeared in a federal court this afternoon in Boston to face allegations of blatant lies in a clumsy attempt to try to destroy evidence.

Now defense lawyers are responding publicly to the charges.

Let's begin our coverage this hour with Brian Todd. He's over at the federal courthouse in Boston -- Brian.

BRIAN TODD, CNN CORRESPONDENT: Wolf, these suspects looked nervous as they appeared in the courthouse behind me this afternoon.

At one point, the judge admonished one of them, saying -- quote -- "I suggest you look at me, rather than looking down." But today that was the least of their problems.

(BEGIN VIDEOTAPE)

TODD (voice-over): Three college classmates of Dzhokhar Tsarnaev's now accused of trying to help their friend by getting rid of evidence related to the Boston Marathon bombings and lying to investigators about it, Dias Kadyrbayev and Azamat Tazhayakov, students from Kazakstan, and American Robel Phillipos named in a criminal complaint, appeared in federal court Wednesday afternoon.

An attorney for Kadyrbayev then spoke to reporters.

ROBERT STAHL, ATTORNEY FOR DIAS KADYRBAYEV: Dias Kadyrbayev absolutely denies the charges. As we have said from the very beginning, he assisted the FBI in this investigation. He is just as shocked and horrified by the violence in Boston that took place as the rest of the community is.

He didn't know that this individual was involved in a bombing. His first inkling came much later. The government allegations, as far as that he saw a photo and recognized them immediately, we dispute and we will be looking forward to proving our case in court. Mr. Kadyrbayev and his family are very sorry for what happened here in Boston and he did not have anything to do with this.

TODD: The complaint says all three admitted that at UMass Dartmouth on April 18, the night before Dzhokhar Tsarnaev was captured, they removed Tsarnaev's backpack from his dorm room, put it in a trash bag and into a dumpster. After a two-day search of a nearby landfill, prosecutors say they found the backpack. Here's a photo. They say the backpack contained fireworks, Vaseline and school papers.

STAHL: He didn't know that those items were involved in a bombing or of any interest in a bombing or any evidential value.

TODD: The complaint says the three friends also destroyed or concealed other objects, including a laptop. The two Kazakhs, seen here in a photo with Tsarnaev in Times Square, also face deportation proceedings for alleged visa violations.

On April 18, the night before Dzhokhar Tsarnaev was captured, the complaint says the three friends saw photos of the bombing suspects on CNN. Prosecutors say one of them, Kadyrbayev, was texting with Dzhokhar Tsarnaev, telling him he looked like the suspect on TV. The complaint says Tsarnaev responded with texts like, "LOL," things that were interpreted as jokes like, "You better not text me" and this -- quote -- "Come to my room and take whatever you want."

I asked attorney Robert Stahl about that last text.

STAHL: It was no signal. I think it means the plain English meaning.

(END VIDEOTAPE)

TODD: But there are other very curious details in this complaint, like a footnote saying that about a month before the Boston Marathon bombings, when the two Kazakh students were eating a meal with Dzhokhar Tsarnaev that Tsarnaev explained -- quote -- "He knew how to make a bomb."

But again the attorneys say their clients had no knowledge that Dzhokhar Tsarnaev had been involved in the Boston Marathon bombings -- Wolf.

BLITZER: But before the bombings also, Brian, this is a little intriguing, shall we say, they were, what, shooting off fireworks together as well? That's about a month or so before the actual Boston Marathon bombing?

TODD: That's right. I have that item in the complaint right here.

And it says that one of them, Azamat Tazhayakov, had seen Dzhokhar Tsarnaev with some fireworks on the bank of the Charles River a couple of months previous. That would have put it back probably around February, and that Tsarnaev, Tazhayakov and others set off the fireworks along the banks of the Charles River. Again, no implication there that they were involved in anything regarding the bombing. But according to this complaint, at least one of them set off fireworks with Dzhokhar Tsarnaev a couple of months beforehand.

BLITZER: I'm sure there are a lot of other leads that the investigating team is going down right now. Brian, thank you.

We're learning more about these three young men, all 19 years old, in custody today and their relationship with Dzhokhar Tsarnaev.

Let's bring in our national correspondent, Susan Candiotti. She's in New Bedford.

What's going on? What's the latest that you're hearing, Susan?

SUSAN CANDIOTTI, CNN NATIONAL CORRESPONDENT: Hi, Wolf.

Well, not surprisingly, the people in this neighborhood can't believe that this would have happened right here where they live. That building that you see over my shoulder, that is the apartment where these suspects who are now charged were living at the time.

That same night, that Friday night on April 19, when police released the photographs of the two bomb suspects, that's when things started to shake around here. Before you knew it, there was a SWAT team that wound up in this very neighborhood rolling down this very street. And neighbors looked out their windows to see what was going on. I talked with one of them about that night.

(BEGIN VIDEO CLIP)

CANDIOTTI: Tell me about the night the FBI came here and swarmed over this neighborhood.

FELIX JORGE, NEIGHBOR: I mean, it was just like the sun was going down, it was pretty gray. And it was actually -- a storm was rolling in right when they were coming in. They lined up a dozen cars down the street in that direction. They had an armored personnel carrier over here. And they had the New Bedford P.D. blocking the street that way and over here.

And nobody could get in and out of their house. They told everybody -- there was one person who was coming out from there. They told them to stay inside. You weren't supposed to be outside. And then they put the loudspeaker, you know, to tell the people to come out of the apartment. And when they did that, all the guns were trained on the house. They were there, and they had the dogs and all that stuff. And it was pretty insane.

CANDIOTTI: Did you see anyone come out?

JORGE: Yes, all the people that were there in the apartment complex came out. It was the two Asian kids and one Asian female, young kids. I had seen them here and there, said hi to them. They were usually cordial, say hi back. Nothing spectacular. I never really talked to them or anything. But they seemed like nice kids, I guess.

CANDIOTTI: What happened when the FBI appeared on the scene that night, and other police? When they picked them out of the house, when they came out of the apartment, then what happened?

JORGE: They made them strip, you know, down to their skivvies.

And they ordered them to walk backwards to the car and to get on their knees. Once they saw they didn't have anything on them, they took them away into an SUV that was waiting, detained them all in different cars. And then the police actually came, the New Bedford P.D. came and took them away. I believe it was -- I saw one of them in the back of a New Bedford police car.

CANDIOTTI: Did you ever hear them say anything?

JORGE: Yes. Yes. I heard them say, we know that he dropped you off yesterday at 4:00. Come out of the building. Nobody's going to get hurt. We just want to, you know, talk to you, this and that.

And I don't know how much talking they were expecting to do with about 15 assault rifles pointed at them.

CANDIOTTI: Now you hear the three students are arrested for allegedly, among other things, throwing out alleged evidence in this case in a dumpster right here on this complex.

JORGE: Yes. There's a really big one over there. That's where they threw it. Everybody throws everything away there. So I'm guessing they probably thought they could sneak it in and nobody would notice, you know?

CANDIOTTI: At a time when everyone was looking for who was responsible for the bombing, to hear that some people are now accused of disposing of possible evidence that belonged to one of the alleged suspects, what do you think of that?

JORGE: I mean, realistically, you have got to think that they might be involved, because, I mean, why would you risk in this kind of climate that we live in, you know, knowing that people can do stuff like this, even if it's your friend, why would you do something so serious like that, disposing of evidence for somebody that could potentially have done a terrorist attack on American soil?

I mean, it's just -- it's insane. So, you have really got to look at it from a regular person's perspective, not as like a friendship perspective. A regular person would see that, like myself, and think, well, they might be part of something bigger, because these guys, they got scholarships. They were in the community. He went to school. He was a regular college student. And then he put a bomb somewhere and did this horrible thing.

(END VIDEO CLIP)

CANDIOTTI: Now, as we have been reporting, Wolf, remember, when the FBI finally got information, leads not only from the suspect that they interviewed at bedside, but also investigative leads which our sources say came in part from their interviews with these suspects, that's what led them to go from the dumpster here to the landfill to start searching for evidence. And in fact, we now know, according to the criminal complaint, that they found that backpack filled with fireworks, several tubes with a fire power -- the powder inside removed. They were also searching for a laptop computer. We know that it was removed from Dzhokhar's dorm room.

But it's unclear at this time what happened to that laptop. My sources have previously told me they didn't find it at the landfill -- Wolf.

BLITZER: We will see what happens, because that laptop could be critically important in terms of trying to determine if this was a broader conspiracy, a limited conspiracy. That laptop would be very, very significant. And the criminal complaint filed today was thunderously silent on the fate of that laptop, whether they found it, they didn't find it. We simply don't know.

You're absolutely right. All right, thanks very much, Susan Candiotti in New Bedford on the scene with us.

Let's dig a little big deeper once again with our national security analyst Juliette Kayyem, the former homeland security adviser for the Massachusetts governor, a columnist for "The Boston Globe."

That picture we have been seeing of the two students from Kazakstan and Dzhokhar Tsarnaev at Times Square when they went there last year -- and we will put it up on the screen. We will show our viewers that picture once again. You know, a lot of people are going to wonder, Juliette, if in fact the two brothers were planning on driving to New York and going to Times Square, as the mayor of New York, the police commissioner in New York later suggested, what was going on? Is this just a coincidence that these three guys were photographed at Times Square?

JULIETTE KAYYEM, CNN NATIONAL SECURITY ANALYST: Yes, Wolf, I do think it's a coincidence, because even the mayor, Bloomberg, said that the decision to go to New York was clearly sort of concocted at the last moments, when they realized that they had been identified by Boston police and federal officials, and were trying to head out of town.

So all of that was spontaneous, the exit strategy, so to speak, and that it is probably a coincidence that they were there with these guys, because they are -- let's also remember, they're 19-year-old boys. They're there the year before. They're visiting America. So, I think the fact -- no one should be worried that there's some sort of larger narrative here about going after these big targets.

The Times Square, the New York City link was really -- came up at the last moments by the brothers as they were trying to escape Boston.

BLITZER: And you think it was also just a coincidence that a month before the Boston bombings, they were shooting off fireworks together, they were talking about how to build a bomb together, as alleged in this criminal complaint today? Was that all a coincidence as well?

KAYYEM: Yes. I think that's not a coincidence. In this instance, I actually think that the complaint alleges that there were fireworks and bombing -- and sort of discussions about bombings.

And the reason they lay that out in the legal document is to essentially say, the three of them that were arrested today knew exactly what they were doing, that this wasn't, oh, we're helping a friend, and that there was enough evidence leading up to the moment, and then -- so that when they get contacted by the younger brother, who says, you know, go into my apartment and do what you need to do, that they had enough knowledge that any rational person would have known that the picture looks like him, they can't find him, he's recently cut his hair, and he tells them to go into his room and do what they need to do.

Putting the pieces together, they were either willfully ignorant, very ignorant or were part of trying to cover it up.

Up next, the online moves that led the authorities to question and later arrest Dzhokhar Tsarnaev's three friends. And a surprising thread coming out of these new arrests, how might Vaseline have been used by the bombing suspects?

(COMMERCIAL BREAK)

BLITZER: One part of the criminal complaint against the three friends of the suspect, Dzhokhar Tsarnaev, jumped out, and I will read it.

Dias Kadyrbayev also found a jar of Vaseline in the room and told Azamat, Azamat Tazhayakov, that he believed Tsarnaev had used the Vaseline to make bombs. At that point, Tazhayakov believed that Tsarnaev was involved in planting the bombs at the Boston Marathon.

Drew Griffin of CNN's Special Investigations Unit is joining us on the phone right now with more on this part of the story.

Drew, what are bomb experts telling you about the use of Vaseline in making a bomb?

DREW GRIFFIN, CNN INVESTIGATIVE CORRESPONDENT: Well, it has a very specific use, Wolf. And that is to separate metal from powder. In this case, it would be the powder from fireworks from any kind of metal that was part of that bomb, perhaps the rim of the pressure cooker.

And the reason you would do that is to prevent any kind of friction that would take place and prematurely detonate the bomb. It shows a certain level of expertise, apparently, on the part of Dzhokhar Tsarnaev, but also seems to suggest that his friends had specific knowledge of this, because when I woke up today, I had no idea that Vaseline was a component in bomb-making -- Wolf.

BLITZER: So if the friends who are now charged with a cover-up, and lying to federal authorities, trying to destroy evidence, if you will, if they knew that Vaseline was a sensitive issue, an ingredient potentially in making a bomb and they decided that was one of the things they were going to throw away in that dumpster, that would suggest that there may be more to this plot than at least federal authorities are laying out in the criminal complaint, as far as we know right now.

GRIFFIN: It certainly begs the question.

And I believe one of them has said that, at some point over a dinner, that Dzhokhar Tsarnaev had explained that he knew how to make a bomb. If at that moment he also explained how, and what the Vaseline was for, certainly, that could explain the knowledge that was passed on. But it is a very -- it's very interesting to me that we went online and looked for various manuals to find out whether or not this was common knowledge.

It is common knowledge among bomb-makers, but we didn't find it to be common knowledge in the kind of online, even "Insight" magazines that are cited in some of this expertise that is passed on. So it's a very specific purpose, a very specific need. And obviously there's very specific knowledge about what that Vaseline was used for.

BLITZER: Amazing.

GRIFFIN: And -- yes. And I just want to add that we have also seen this in the past. In Najibullah Zazi, in testimony of one of the co- conspirators, Vaseline was mentioned as being one of the materials identified at an al Qaeda camp in FATA, Pakistan. So it has been used in the past. It's just very specifically used.

BLITZER: All right, Drew, thanks very much. Good points indeed. Lots of intriguing questions to explore.

When we come back, the father of one of these new suspects speaking to CNN about his son's links to the Boston bombing investigation.

Plus, a 747 falls from the sky. We have stunning video of the fiery crash and what may have caused it.

(COMMERCIAL BREAK)

BLITZER: Let's get back to the breaking news right now.

Three friends of the Boston bombing suspect, Dzhokhar Tsarnaev, are charged with a cover-up. Two of them are from Kazakstan. It's a former Soviet Union republic neighboring Russia, and the Dagestan area, where the Tsarnaevs live.

Our Nick Paton Walsh is joining us once again from Moscow.

What are we hearing now from the father of one of these students from Kazakstan who was arrested today, the father of Dias Kadyrbayev? He's speaking out, I take it?

NICK PATON WALSH, CNN CORRESPONDENT: Well, this is an interview that happened in Kazakstan a week ago, Wolf, before these charges became clear. Murat Kadyrbayev, the father of Dias, talking about why his sons have been questioned by police after the bombings initially, and then going on to explain why they were being held on immigration charges. He said quite simply they are there on a student visa and they have been skipping class, like prosecutors said today in the complaint. And that violates the terms of the student visa.

And the first questioning had simply happened because, like everybody else in that university, those two boys were being talked to by the police to see what they may have actually seen. Interestingly, though, he does address this issue of the rather outlandish number plate on the BMW that Azamat Tazhayakov shared, saying that was simply a gift from some Spanish friends.

I quote him from saying: "A gift from Spanish friends, it turned out. It is an unusual gag, a joke, which can at the moment be turned into something dramatic." Bit of an understatement there, but, of course, that said way before these charges emerged, Wolf.

BLITZER: Have we gotten any reaction whatsoever from Almaty in Kazakstan, the former capital where these two students are from? Anyone saying anything about the arrest of the two Kazakh students?

WALSH: Wolf, at this point, there has been no comment. It is a public holiday there, much of the former Soviet Union, and it was late in the evening when news of this broke there.

The father has previously said that these -- his son -- as you would imagine in a father speaking about his own child -- of outstanding character, good at math, helping other students, creative, writing his own songs, liking snowboarding in the winter, tennis in the summer

I should point out here Kazakstan doesn't really have a problem with extremism. It has occasional issues, but compared to the other Central Asian countries, it's significantly more stable and less bothered by it. So, I think really Kazakstan here is simply where these guys hailed from, rather than necessarily at this point seeming to be part of the broader picture, Wolf.

BLITZER: All right, Nick, thanks very much, Nick Paton Walsh reporting for us from Moscow.

And still ahead, the mistakes made by Dzhokhar Tsarnaev's friends that led authorities right to them, beginning with a sudden change online.

And the arrest record that may be haunting the widow of Tamerlan Tsarnaev. She's still a focus of this bombing investigation.

(COMMERCIAL BREAK)

BLITZER: Happening now, breaking news we're following, new cover-up charges in the Boston bombing investigation. What's next for three friends of Dzhokhar Tsarnaev? Will they be squeezed for information?

Plus, how social media led authorities to question these three new suspects. Stand by for more mind-boggling details from the criminal complaint.

And the photos only tell part of the story. We now have rare video showing a 747 crash into the ground and explode in a fireball.

I'm Wolf Blitzer. You're in THE SITUATION ROOM.

Three of Dzhokhar Tsarnaev's friends are in jail right now. They're accused of trying to throw investigators off the Boston bombing suspect's trail. The breaking news we're following this hour, the three 19-year-old men appeared in court this afternoon on charges of obstructing justice and lying to federal investigators.

According to a detailed criminal complaint, they agreed to throw out Tsarnaev's laptop and a backpack filled with fireworks. Lawyers for the three suspects suggest the complaint is filled with lies. They say their clients are cooperating.

(BEGIN VIDEO CLIP)

HARLAN PROTASS, ATTORNEY FOR AZAMAT TAZHAYAKOV: My client, Azamat Tazhayakov, feels horrible, and was shocked to hear that someone he knew at the University of Massachusetts-Dartmouth was involved with the Boston Marathon bombing, just like many other individuals who were interviewed on campus. He has cooperated fully with the authorities and looks forward to the truth coming out in this case.

ROBERT STAHL, DIAS KADYRBAYEV: Mr. Kadyrbayev and his family are very sorry for what happened here in Boston, and he did not have anything to do with this. He did not know that this individual was involved in a bombing.

(END VIDEO CLIP)

BLITZER: Let's dig a little bit deeper, get some more information on today's dramatic new developments in the Boston bombing investigation. Our national correspondent, Deborah Feyerick, is working her sources. Deb, what are you learning?

DEBORAH FEYERICK, CNN NATIONAL CORRESPONDENT: Well, Wolf, we can tell you that one of the students charged today, Dias Kadyrbayev, he was handcuffed and taken in for questioning hours before Dzhokhar Tsarnaev was even found by federal agents and police. And of course, the young man was found cowering and bleeding in a boat.

But a source tells us that 3 a.m. Friday morning, Kadyrbayev, you see there, removed a photo from his Facebook page. And the photo showed him and Tsarnaev together at a kitchen table. That's the photo he took off his Facebook page. Then, just before dawn, with Tsarnaev still on the run, the two friends apparently changed their Facebook profile picture, within 15 minutes of each other, 4:50 and 5:04 respectively. That's always been curious to investigators.

Now, could Tsarnaev have replaced his with one in which he is seen wearing an iron mask? That one right there. Investigators have been looking into the possibility that perhaps the two friends were communicating with one another while Dzhokhar Tsarnaev was on the run. And what we do know from reading the criminal complaint is that Tsarnaev fled his dorm room Thursday, right after the FBI released photos. He and Dias texted one another, Dias saying that Dzhokhar looked a lot like one of the suspects. Dzhokhar responds with a text, saying "LOL," which is shorthand for "laugh out loud." And he tells Dias, "You better not text me," and "come to my room and take whatever you want."

Well, Dias thinks that his friend is actually joking but still, according to the complaint, he shows up at Dzhokhar's dorm room, along with the two others, Azamat Tazhayakov and Robel Phillipos. Dzhokhar's roommates let -- his roommate lets the three men in. They allegedly watch a movie. And then, according to the criminal complaint, Dias notices a backpack containing empty fireworks, and he realizes that his friend Dzhokhar was involved in the marathon bombing.

So what Dias does is he takes the backpack and Dzhokhar's computer back to his own apartment, the one that he shares with Azamat, and they throw those two things away. He tells investigators, Wolf, that the reason they did that is because they did not want Tsarnaev to get into trouble -- Wolf.

BLITZER: Did you say -- I just want to clarify this -- that when he replaced his photo of that iron mask, he was trying to send a signal to someone by doing that? Is that what you're suggesting?

FEYERICK: Well, what's so interesting, this is -- you know, investigators look at the things that simply don't make sense. Because when they don't make sense, there may be a reason to it.

The fact that both he and Dzhokhar Tsarnaev changed their Facebook profile pictures within 15 minutes of each other, that has been baffling to them. Why did they do that? And why, you know, at such an odd time, 4:50 and 5:04 in the morning Friday while Dzhokhar Tsarnaev is still on the run. So they're looking into that. They want to understand why that was. And for example, you know, whether in fact they were communicating with one another.

BLITZER: Deborah Feyerick, thanks very much. Intriguing stuff.

Let's get some more now with our national security analyst, Tom Fuentes, a former assistant FBI director, and our senior legal analyst, Jeffrey Toobin.

Tom, what do you think about that last point, that iron mask? Is that possible he put that on in the middle of the night in order to communicate some sort of signal to someone?

TOM FUENTES, CNN NATIONAL SECURITY ANALYST: I'm not sure if it communicates a signal, if Tsarnaev doesn't have access to his Facebook page or e-mail or any other computer at that point. It may not be a signal that way. It may just be that they think if they change or deleted some of these accounts of photographs or entries on their social media pages, it somehow is gone and no one will ever find it. And, you know, the common investigative techniques is always get phone records, Internet records, financial records, and many times people are missing the fact that all of these exchanges of photos and information on Facebook or other social media pages are there for way longer -- well, for longer than they want. That's for sure.

BLITZER: You think you're deleting, but not necessarily.

FUENTES: Right.

BLITZER: All right. Listen to this. I'm going to play a little clip. This is from the attorneys representing two of the suspects. Listen to this.

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: Did they take the knapsack and bring it to the dump and dump the fireworks and the knapsack?

STAHL: We -- we are not saying that. Mr. Kadyrbayev told the FBI about that. He did not know that those items were involved in a bombing, or of any interest in a bombing or any evidential value. So that's all we have to say about that.

But we are the ones, Mr. Dias Kadyrbayev, cooperated with all law enforcement when they came to him, without the benefit of counsel, to assist them in their investigation of this horrible tragedy.

UNIDENTIFIED MALE: Did they know that Tsarnaev also know how to make bombs, or that the powder that was in the fireworks, and the Vaseline could also be used for bomb making?

STAHL: No.

(END VIDEO CLIP)

BLITZER: The criminal complaint, on the other hand, says this. And I'll put it up on the screen: "Kadyrbayev located a backpack that contained an emptied-out cardboard tube that Tazhayakov described as fireworks. This discovery frightened Tazhayakov, because the powder had been emptied from the tube. Kadyrbayev also found a jar of Vaseline in the room and told Tazhayakov that he believed Tsarnaev had used the Vaseline to make bombs."

Jeffrey, it sounds like very different stories and very different conclusions there.

JEFFREY TOOBIN, CNN LEGAL ANALYST: Well, I think the conclusions are different. The stories aren't really all that different. Mr. Stahl, the lawyer, is acknowledging that this new defendant removed the backpack and got rid of it. What he's disputing is what his intent was in doing that.

The FBI, in its allegations, says he was doing it to hide evidence, to help out Tsarnaev. What Mr. Stahl is saying is there's some other innocent explanation. So he is trying to set up an intent defense, that, yes, he did do this, but his intent was innocent. Obviously we have to see how the evidence plays out to see if the defense have any merit.

BLITZER: But in the complaint, Tom, it says specifically Kadyrbayev also found a jar of Vaseline in his room and told Tazhayakov that he believed Tsarnaev had used Vaseline to make bombs. Now, that's a pretty specific detail. Only bomb makers supposedly know that Vaseline is an important ingredient.

FUENTES: A specific detail, but they're not saying how he knows that Vaseline is a component of bomb making. It just says that he cites that "I see Vaseline. It's used in making a bomb." How does he know that?

So I would think that the authorities know more about how he knows that, and that will come later. But they're just using the bare minimum in the complaint now, just to hold them and bring the charge. We'll hear more about it later.

BLITZER: We certainly will. Stand by for a moment. There's more coming up. We're getting some new details just coming into THE SITUATION ROOM about what Tamerlan Tsarnaev's wife did after the FBI released his picture for the world to see. Gloria Borger is getting new information. Stand by.

(COMMERCIAL BREAK)

ANNOUNCER: This is CNN breaking news.

BLITZER: There's an important development. CNN's Gloria Borger has been working this story. She's digging into the FBI's investigation of Tamerlan Tsarnaev's widow. And Gloria's joining us now.

What are you learning about Katherine Russell Tsarnaev?

GLORIA BORGER, CNN POLITICAL ANALYST: Well, my colleague, Deborah Feyerick, and I are learning that she spoke on the phone to her husband, Tamerlan Tsarnaev, following the FBI release of his photographs that went, of course, worldwide after the bombing.

The nature of that conversation, Wolf, is a matter of investigation by federal law enforcement authorities. There's also some concern, according to our sources, that she spoke with her husband. But she didn't contact them.

She very much remains a woman of mystery in all of this. A question of, what, if anything, did she know? They're clearly speaking with her quite extensively, or trying to. And I was told she could be a trove of information, really, about his affiliations and his activities, if nothing else.

BLITZER: Is she cooperating? Is she talking to the FBI? Is she sharing these kinds of details?

BORGER: They're -- I know Erin McPike is on the ground there. There are some reports that she was cooperating, and is no longer, but we knew that -- we know that authorities have been seen leaving her home, with DNA kits, et cetera. So I assume that there has been a lot of communication.

And I know for a fact that federal law enforcement wants more, because they want to know what conversations or encounters she had with the suspects after the attack.

BLITZER: Let's go out to the scene. Erin is out there, outside the home. What have you seen today? What have you seen over there, Erin?

ERIN MCPIKE, CNN CORRESPONDENT: Well, Wolf, it's not the same kind of activity that we saw last weekend at the beginning of this week. We're seeing far fewer federal vehicles.

But Wolf, I would point out that Katie Russell's team of attorneys and everyone surrounding her have gotten a bit savvier as far as the media is concerned. Just today we learned that there is a press representative who's now representing Katie Russell, and her attorney is now dealing with the crush of media requests that they're getting.

And the other thing I would add, Wolf, is that I spoke to the police chief of the North Kingtown Police Department just yesterday, and he said that local police have been coming by quite a bit, because this has been such a disruption in this community that they are concerned for the safety of the Russell family. Just because they don't want anybody from the community taking out any sort of action on the Russell family, Wolf.

So it's a different operation today than we've seen in the past days, Wolf.

Jeff, first to you. If she -- she saw the picture on television of her husband and her brother-in-law, and then she spoke with her husband, Tamerlan Tsarnaev, on the phone afterwards, but didn't call the FBI or law enforcement, is she in trouble?

TOOBIN: Probably not. That's not a crime, to fail to report someone who is wanted by -- wanted by the police. Again, we talked about this earlier. There is a moral component to that, obviously, but I'm not aware of any crime that that would constitute. It certainly is something that the investigators would want to talk to her about.

But that alone, the fact that they had this conversation, and she did not report him, is not a prosecutable event -- event, as far as I can tell.

BLITZER: Even though within a matter of a few hours, there was a killing of an MIT police officer, and the allegation is that Tamerlan Tsarnaev, her husband, went out and killed Sean Collier, this MIT police officer, literally in cold blood to try to, supposedly, steal his weapon?

TOOBIN: Unless the authorities could prove that she was a co- conspirator, that she knew they were going to attack a police officer, that she knew they were building bombs and firing guns, I don't see any way that that could be something she could be prosecuted for. Obviously, the great unknown here is, what did she say? Did she further the conspiracy or did she just call her husband and say, "Your name is in the news. What the -- your face is in the news. What the heck is going on?" That certainly wouldn't be a crime.

If she was saying, "How can I help you commit more crimes?" that would be. He's dead. She's not talking. So we don't know what was said between them.

BORGER: And let me add to what Jeffrey is saying, because he's absolutely right. We don't know the nature of the conversation. We don't know, you know, what she said to her husband. It's, of course, a concern to authorities that she didn't call them. But could they prosecute her for bad behavior? No.

BLITZER: You were a former FBI assistant director, Tom. The fact that -- I guess it's a fact that she calls her husband, she speaks with her husband, but she doesn't tell law enforcement, "Hey, I know who this guy is that you're looking for. He happens to be my husband," what does that -- what does that -- how does that fit into this investigation?

FUENTES: Well, I think, Wolf, it tells you that even, in a high- ranking position in the FBI, we can't read minds. We don't know what she's thinking and what the nature of that call was. We don't know what Tamerlan is talking about with his mother. So when you look at these records, you see family members talking to each other, you just don't know.

Is it a criminal conversation? Conspiring together, as Jeffrey Toobin just mentioned? Or is it, "Hey, honey, bring home some milk tonight? Are you done with the bombing?" You know?

BLITZER: I will just wrap it up by pointing out that she's probably saying to herself, "I wish I would have called the FBI." Maybe Tamerlan Tsarnaev would have been alive, maybe Sean Collier, the police officer, would have been alive if she would have just dialed 911 and said, "You know what? I know who these two guys are."

She apparently didn't do that. And she's going to have to live with that the rest of her life.

BLITZER: But she does have an interesting story to tell, no matter what. And federal authorities are clearly...

BLITZER: I'm sure she's pretty upset that she didn't do the right thing at that moment. All right, guys, thanks very much. We're going to continue to follow the breaking news here.

We're also following some other important news, including some chilling video of a 747 plunging to earth only seconds after takeoff. Up next, we're going to look at possible causes for this fiery and deadly crash.

(COMMERCIAL BREAK)

BLITZER: The stunning and deadly crash of a 747 cargo plane all caught on tape falling from the sky seconds after taking off from a U.S. air base in Afghanistan. Our Pentagon correspondent, Chris Lawrence, has some chilling video to share with us. Chris, what do we know about this crash?

CHRIS LAWRENCE, CNN CORRESPONDENT: We're now learning that the plane likely never got above 1,500 feet. Now that said, this video is extremely graphic. In fact, even officials who have investigated crime scenes say they've never seen anything like it.

(BEGIN VIDEOTAPE)

LAWRENCE (voice-over): The video is dramatic and disturbing. A 747 just stalls and falls back to earth.

While CNN can't fully confirm how authentic the video is, it does appear to show a cargo plane that crashed Monday in Afghanistan. That crash killed seven American crewmen including Brad Hassler.

UNIDENTIFIED MALE: If I could trade places with him so that he could be with his family, I would in a heartbeat.

LAWRENCE: That's Hassler's brother, who says Brad's wife is pregnant.

UNIDENTIFIED MALE: This is his daughter and his youngest two. But who we don't see in here is the baby that's on the way who we expect to see in October.

LAWRENCE: The 747 was bound for Dubai, carrying equipment as part of the U.S. military's drawdown from Afghanistan. The civilian cargo plane was loaded with five MRACKs (ph), each weighing about 27,000 pounds.

LAWRENCE: Steven Wallace is the former director of the FAA's accident investigation unit. He says there's no forgiveness in a plane's center of gravity.

WALLACE: Basically, there can only be so much weight at each part of the plane. So it's critical the total weight be within the limit and that the plane be balanced.

LAWRENCE: The 747 can take off a couple different ways. When it's carrying passengers, it will take four to five minutes to reach 15,000 feet. But in Afghanistan, there's always the danger of being shot out of the sky. So the pilots need to gain as much altitude as possible while they're still over Bagram. A 747 carrying cargo can reach altitude almost two minutes faster.

WALLACE: The typical concern with a cargo aircraft, and this has caused accidents before, is that when the airplane is rotated with the nose up, the cargo moves aft if it's not properly secured. LAWRENCE: Cargo is chained down. But if an attachment point fails, it could shift.

WALLACE: We don't know that that happened here. That has happened in prior accidents. Then the airplane becomes uncontrollable.

LAWRENCE: It's much harder to have a massive shift of weight on a commercial 747 because the passengers and the weight are evenly distributed in chairs.

(END VIDEOTAPE)

LAWRENCE: Now the voice recorder and the flight data recorder are in the back of the plane. And they are designed to withstand extreme impact as well as survive very high temperatures like that fireball that we just saw. That will be the key for investigators from the NTSB, Wolf, who have gone to Afghanistan to try to figure out exactly what caused this crash.

BLITZER: It will be a very important investigation. We want to learn from whatever happened there, Chris. Thanks very much.

A quick note on an another aviation story we're watching here in Washington. The FAA furloughs are officially now suspended after President Obama signed a bill giving the FAA permission to move money from other accounts to keep air traffic controllers on duty. The furloughs were blamed for widespread flight delays. Congress approved the bill on Friday.

JEANNE MOOS, CNN CORRESPONDENT (voice-over): If you think you're sagging, consider Obie, the obese Dachshund. Used to be you could actually hear his belly dragging.

NORA VANATTA, OBIE'S OWNER: Good boy.

MOOS: But on Tuesday, Obie dragged himself to Oregon expert vets and went under the knife after months of weight loss.

DR. ALON KRAMER, OPERATED ON OBIE (via phone): It is a modified tummy tuck, yes. Because we removed redundant skin and had to reconstruct.

MOOS: The idea wasn't to make Obie lose weight. He had already done that. At his worst, screen left, he weighed 77 pounds. Screen right, he dropped 40.

(on camera): Obie's previous owners were elderly and ill. They overfed him, practically killing him with kindness. (voice-over): Eventually, Obie was adopted by a veterinary technician. Nora Vanatta had to fight for custody of Obie. He got praised just for managing to waddle down the ramp Nora set up.

VANATTA: Good job!

MOOS: Frankly, Obie's belly made him look like something that had washed up on the beach. Thanks to an overweight management formula, fed to Obie in a dish that slows the dog down as he eats, he started losing weight. He didn't appreciate veggies.

VANATTA: Eat your carrots.

(DOG WHINING)

MOOS: And he was too fat for the treadmill, demonstrated by Nora's other Dachshund, but over eight months...

VANATTA: Look at him go!

MOOS: ... look at his weight go down. Here he is at 41 pounds. By the time of the surgery, he weighed 37 1/2. But there was no way this extra skin and flab would ever disappear on its own. Plus, it was black from inflammation and infection. So in a two-hour operation...